The present invention relates to a test tool, used for the testing of detectors and more particularly fire or smoke detectors.
Detectors are designed to detect substances which are carried in the air, or changes to the air passing through its vents/openings, for example. In fire protection, a heat detector which detects the rise in temperature of the air (and smoke) which passes through it while other detectors may sense products of combustion present in the air such as smoke. The air is normally expected to flow laterally through the vents of the device, and hence the vents are made open to the sides. Such devices are commonly mounted on ceilings to detect fires, since the heat, smoke and gases from a fire will rise to the ceiling and then move along it, due to convection currents entering the detector from the side.
Testing detectors which are mounted on ceilings (without removing them) is often achieved from the ground beneath the detector using access poles and special equipment. This naturally means that the approach is likely to be from the underside of the detector. To introduce a stimulus into the detector from underneath is not in keeping with the design of the detector, which is best suited to laterally-introduced stimuli.
The present invention provides an arrangement whereby the introduction of a stimulus into the detector under test is lateral, even though the tool may be accessing from beneath.
In a preferred embodiment, a stream of air which carries the stimulus for the detector is generated in the tool and ducted in such a fashion that it flows transversely across a cup, which itself is placed over the detector. The cup is preferably made from transparent material so that the detector may be seen during the test, since often an LED is mounted on the detector, which indicates when an alarm status has been reached.